Drive device



Sept. 1950 F. s. PRICE 2,522,960

' DRIVE DEVICE Filed Nov. 14, 1949 INVENTOR FREDERICK 5. PRICE ATTORNEY bolted to the base as shown at 3.

Patented Sept. 19, 1950 s PATENT OFFICE DRIVE DEVICE Frederick S. Price, St; Louis County, Mo.

Application November 14, 1949, Serial No. 127,063

4 Claims." (01. 51-26) This invention relates to. drive devices, and particularly to such a device for use in sharpening lawn mower blades. The principal object of the invention is to produce a drive device which is portable and which can be adjusted to sharpen the blades of'mowers of various sizes, the most important feature thereof being its adjustability as-to height to suit any type of lawn mower. Another advantage of my device is the ease and speed with which this adjustment can be made, that is, by merely loosening a screw and moving to the desired position a shaft which supports a portion of the mechanism and then tightening said screw to retain the rod in that position. As farsas I am aware, I am the first to incorporate this feature of adjustabilit in adevice of this type. Another advantage of my invention is the simplicity of its construction, embodying few parts and those of such a nature as to withstand long usage without the necessity of repairs or replacements,

.In the drawing Fig. 1 is a top plan view of my drive device as it appears in operative position, and in association with a motor.

Fig. 2 is a side elevation of the device, illus-.

I. the collar I3; as seen most clearly in Fig. 1, and

trating particularly the motion transmitting" Fig. 4 is an enlarged, cross-sectional view taken on line 44, Fig. 1.

The invention comprises a base I, on which is mounted a rigid, vertical support 2 which is A hollow cylinder 4 is rigidly mounted on the support 2 .and at a right angle thereto, and a shaft 5,

it is movable therewith upon rotation of the shaft 5, said plate .9 beingapproximately as wide as the, combined width of the cylinder -4 and the collars 6 and "I," and said plate 9 is cut out,

as shown at III, to permit it to move freely' about the stationary cylinder 4.

At the outer free end of the plate 9 a horizontally disposed cylinder II is welded thereto. A rotatable shaft I2 is positioned in the cylinder II and extends outwardly beyond each" end of saidcylinden-yand adjacent one end of said cylinder I l a retaining collar I3 is rigidly secured to the shaft to hold the cylinder II place. ,The shaft l2is of such. length as to'ex tend outwardly aconsiderable' distance beyond are adapted to engage retaining pins l2" on the shaft I2, said coupling being adapted to connect the shaft I2 with the mechanism of the lawn mower L."

On the shaft 5 and adjacent the collar 6 there is mounted a gear wheel I6 which rotates on the shaft 5, and another gear wheel ll, of larger diameter, is mounted on the shaft l2 and rotatable therewith, the gear wheels I6 and I! being inengagement with each other. Also mounted on the shaft 5 and rotatable thereon I provide a pulley I8 which is positioned between the gear wheel I6 and a bearing l9 secured to the shaft 5 as a retaining member for the pulley I8, the gear wheel I6 and pulley lflbeing secured together. that both the gear wheel I6 and the pulley I8 are rotatable on the shaft 5, but the bearin I9 is stationary thereon.

A shaft 20 is rotatably mounted in a pair of bearings 2| which are secured to the base I by means of bolts 22, said bolts and the shaft therein being spaced away a slight distance from thesupport 2, as seen in Figs. 1 and 2. Near the end of the base I which is closest to the shaft 2|] I provide a spiral spring 23 which surrounds a vertical post 24 rising from the base I, said post 24 being screwthreaded at its upper portion. A U-shaped element 25 has its rounded end in engagement with the upper portion of the post 24 and resting upon the spiral spring 23,

1 and the legs 26 of said element 25 extend inwardly. Above said U-shaped element a washer 21 is positioned on the post 24, and a threaded nut 28 is screwed onto the upper portion of said post above the washer 21, so that when the nut 28 is screwed down it will depress the U-shaped element 25 by virtue of its position on the: spiral spring 23.

A platform 29 rests upon and is secured to the legs 26 of the U-shaped element 25 and also to the rotatable shaft 20, and a motor M of any preferred type rests upon and is secured to the platform 29. A pulley 3!] is mounted upon the motor shaft 3| and rotates therewith, and a belt 32 connects the pulleys I8 and 30, the pulley 30 being of considerably smaller diameter than the pulley I8.

In operation the procedure is as follows: g

The lawn mower is attached to my drive device through the agency of the coupling I4, andin order to accomplish this the cylinder II. in which the shaft I2 is positioned, is moved to the required height, carrying the coupling I4 with it. This movement of the cylinder II is transmitted to the collars 6 and I through the From the above it will be understood plate 9, the shaft 5 being rotated at the same time, and the shaft is then locked at the resultant position by screwing tight the bolt 33 which extends through the cylinder 4 to the shaft 5. It will be understood from the above that this looks the shaft I2 and the coupling thereon at the correct height for attachment to the lawn mower. v,

The motor M is now started, and as the motor shaft 3! rotates, the pulley 31! rotates therewith in a clockwise direction, and this motion is transmitted through the belt 32 to the pulley l8 and to the gear wheel 16 attached thereto. As the gear wheel [6 rotates in a clockwise direction,

the gear wheel I which is in association with the gear wheel I6, is rotated in a counterclockwise direction, and this movement is transmitted to the shaft 12 and thence to the mechanism of the lawn mower secured thereto by the coupling [4.

The mechanism of the lawn mower forms no part of this invention, but it is well known that the blades of a mower perform their shearing function through a lapping movement in a clockwise direction against the cutter bar of the mower. When coupled to my device asabove described, this clockwise movement of the lawn mower blades is reversed, so that they strike the cutter bar with a counterclockwise lapping movement. The cutter bar of the lawn mower has previously been covered with a gritty substance, and as the blades move against the cutter bar as above described, they are sharpened through the agency of the gritty substance on the cutte bar.

The motor M usually operates at a speed which is greater than desired, and this speed is reduced by virtue of the difference in diameter between the two pulleys 30 and i3, and is still further reduced by the difference in diameter between the gear wheels l6 and H. In order to obtain the best results, the belt 32 must be kept taut. Through continued use the belt may become loosened, and in order to tighten it the bolt 28 is screwed down on the U-shaped element 25,- and the pressure thus exerted on the spring 23 permits said U-shaped element to be lowered. This results in a lowering Of the platform 29, which movement is facilitated by its attachment to the rotatable shaft 2l', and consequently the motor M and its shaft 3! are also lowered, thus increasing the tension of the belt 32.

When the lawn mower blades have been sufficiently sharpened, the motor M is stopped and the mower may be uncoupled from the drive device through release of the coupling I4.

I claim:

1. A drive device for engagement with a lawn mower to sharpen the blades thereof and including a motor having a shaft rotatable in a clock wise direction, said drive device including a rotatable element mounted on said motor shaft, a second rotatable element, and means for connecting said rotatable elements so that said clockwise motion of the motor shaft is transmitted to Said rotatable elements, a member attached to and rotatable with the. second-named rotatable element and a second rotatable member associated therewith so as to translate'the clockwise motion into anti-clockwise motion, said second rotatable member being mounted on a swingable shaft to transmit said anti-clockwise motion to said shaft, and means on said swingable shaft for transmitting said anti-clockwise motion to the lawn mower blades.

2. A drive device for engagement with a lawn mower to sharpen the blades thereof and including a motor having a shaft rotatable in a clockwise direction, said drive device including a pair of pulleys and means for connecting them and one of said pulleys being mounted on said motor shaft so that said pulleys receive clockwise motion therefrom, a gear wheel attached to one of said pulleys and a second gear wheel associated therewith to translate said clockwise motion into anticlockwise motion, oneof said gear wheels being mounted on a stationary shaft and the other gear wheel being mounted on a rotatable shaft, and connecting means between said gear shafts to permit swinging movement of said rotatable shaft, and a coupling on said swingable shaft to transmit said anti-clockwise motion to the blades of said lawn mower. I

3. A drive device for engagement with a lawn 1 mower to sharpen the blades thereof and includone of said pulleys being mounted on said motor shaft so that said pulleys receive clockwise motion therefrom, a gear wheel attached to one of said pulleys anda second gear wheel associated therewith to translate said clockwise motion into anti-clockwise motion, one of said gear wheels being mounted on a stationary shaft and the other gear wheel being mounted on a rotatable shaft, and connecting means between said gear shafts to permit swinging movement of said rotatable shaft, and a coupling on said swingable shaft to transmit said anti-clockwise motion to the blades of said lawn mower; a support for said motor, and means for adjusting said support to increase or decrease the tension of the connecting means between said pulleys.

4. A drive device for engagement with a lawn mower to sharpen the blades thereof and including a motor having a shaft rotatable in a clockwise direction, said drive device including a pair of pulleys and means for connecting them and one of said pulleys being mounted on said motor shaft so that said pulleys receive clockwise motion therefrom, a gear wheel attached to one of said pulleys and a second gear wheel associated therewith to translate said clockwise motion into anti-clockwise motion, one of said gear wheels being mounted on a stationary shaft and the other gear whe'el being mounted on a rotatable shaft, and connecting means between said gear shafts to permit swinging movement of said rotatable shaft, and a coupling on said swingable shaft to transmit said anti-clockwise motion to the blades of said lawn mower; a support for said motor, and means for adjusting said support to increase or decrease the tension of the connecting means between said pulleys, said pulleys being of different diameters and said gear wheels being of different diameters to control the speed of rotation transmitted to the blades of said lawn mower.

UNITED STATES PATENTS Number Name Date 1,497,650 Mead June 10, 1924 1,866,794 Bierman July 12, 1932 2,110,637 Simmons et a1 Mar. 8, 1938 

